[en] A first report aims at shedding a light on existing projects of geothermal valorisation in France and in Europe (Germany, Netherlands, UK, Norway, Spain, Poland) and on studies performed in France, and at identifying favourable conditions and potential deadlocks related to the valorisation of former mining sites. A second report outlines the context and stakes of the conversion of hydrocarbon exploration and exploitation drillings into geothermal works, discusses the associated risks, presents the different technologies of exploitation of the geothermal resource, reports returns on experience in France and abroad (Poland, Switzerland, Germany, New-Zealand, USA), states recommendations for these conversions, and proposes an overview of the situation and the implementation of a methodology of data analysis for such conversions. The third report reports a study of the regulatory framework of the conversion of oil drilling or mining sites into geothermal works, and the study of two potential cases of conversion in closed loop and in open loop. The next report presents the project of valorisation of former mining sites, proposes an inventory and a characterization of mining emergences and mine shafts in France